1 /*
2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_RUNTIME_OS_HPP
26 #define SHARE_VM_RUNTIME_OS_HPP
27
28 #include "jvmtifiles/jvmti.h"
29 #include "prims/jvm.h"
30 #include "runtime/extendedPC.hpp"
31 #include "runtime/handles.hpp"
32 #include "utilities/macros.hpp"
33 #ifndef _WINDOWS
34 # include <setjmp.h>
35 #endif
36 #ifdef __APPLE__
37 # include <mach/mach_time.h>
38 #endif
39
40 class AgentLibrary;
41
42 // os defines the interface to operating system; this includes traditional
43 // OS services (time, I/O) as well as other functionality with system-
44 // dependent code.
45
46 typedef void (*dll_func)(...);
47
48 class Thread;
49 class JavaThread;
50 class Event;
51 class DLL;
52 class FileHandle;
53 class NativeCallStack;
54
55 template<class E> class GrowableArray;
56
57 // %%%%% Moved ThreadState, START_FN, OSThread to new osThread.hpp. -- Rose
58
59 // Platform-independent error return values from OS functions
60 enum OSReturn {
61 OS_OK = 0, // Operation was successful
62 OS_ERR = -1, // Operation failed
63 OS_INTRPT = -2, // Operation was interrupted
64 OS_TIMEOUT = -3, // Operation timed out
65 OS_NOMEM = -5, // Operation failed for lack of memory
66 OS_NORESOURCE = -6 // Operation failed for lack of nonmemory resource
67 };
68
69 enum ThreadPriority { // JLS 20.20.1-3
70 NoPriority = -1, // Initial non-priority value
71 MinPriority = 1, // Minimum priority
72 NormPriority = 5, // Normal (non-daemon) priority
73 NearMaxPriority = 9, // High priority, used for VMThread
74 MaxPriority = 10, // Highest priority, used for WatcherThread
75 // ensures that VMThread doesn't starve profiler
76 CriticalPriority = 11 // Critical thread priority
77 };
78
79 // Executable parameter flag for os::commit_memory() and
80 // os::commit_memory_or_exit().
81 const bool ExecMem = true;
82
83 // Typedef for structured exception handling support
84 typedef void (*java_call_t)(JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
85
86 class MallocTracker;
87
88 class os: AllStatic {
89 friend class VMStructs;
90 friend class JVMCIVMStructs;
91 friend class MallocTracker;
92 public:
93 enum { page_sizes_max = 9 }; // Size of _page_sizes array (8 plus a sentinel)
94
95 private:
96 static OSThread* _starting_thread;
97 static address _polling_page;
98 static volatile int32_t * _mem_serialize_page;
99 static uintptr_t _serialize_page_mask;
100 public:
101 static size_t _page_sizes[page_sizes_max];
102
103 private:
104 static void init_page_sizes(size_t default_page_size) {
105 _page_sizes[0] = default_page_size;
106 _page_sizes[1] = 0; // sentinel
107 }
108
109 static char* pd_reserve_memory(size_t bytes, char* addr = 0,
110 size_t alignment_hint = 0);
111 static char* pd_attempt_reserve_memory_at(size_t bytes, char* addr);
112 static void pd_split_reserved_memory(char *base, size_t size,
113 size_t split, bool realloc);
114 static bool pd_commit_memory(char* addr, size_t bytes, bool executable);
115 static bool pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
116 bool executable);
117 // Same as pd_commit_memory() that either succeeds or calls
118 // vm_exit_out_of_memory() with the specified mesg.
119 static void pd_commit_memory_or_exit(char* addr, size_t bytes,
120 bool executable, const char* mesg);
121 static void pd_commit_memory_or_exit(char* addr, size_t size,
122 size_t alignment_hint,
123 bool executable, const char* mesg);
124 static bool pd_uncommit_memory(char* addr, size_t bytes);
125 static bool pd_release_memory(char* addr, size_t bytes);
126
127 static char* pd_map_memory(int fd, const char* file_name, size_t file_offset,
128 char *addr, size_t bytes, bool read_only = false,
129 bool allow_exec = false);
130 static char* pd_remap_memory(int fd, const char* file_name, size_t file_offset,
131 char *addr, size_t bytes, bool read_only,
132 bool allow_exec);
133 static bool pd_unmap_memory(char *addr, size_t bytes);
134 static void pd_free_memory(char *addr, size_t bytes, size_t alignment_hint);
135 static void pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint);
136
137 static size_t page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned);
138
139 // Get summary strings for system information in buffer provided
140 static void get_summary_cpu_info(char* buf, size_t buflen);
141 static void get_summary_os_info(char* buf, size_t buflen);
142
143 static void initialize_initial_active_processor_count();
144 public:
145 static void init(void); // Called before command line parsing
146 static void init_before_ergo(void); // Called after command line parsing
147 // before VM ergonomics processing.
148 static jint init_2(void); // Called after command line parsing
149 // and VM ergonomics processing
150 static void init_globals(void) { // Called from init_globals() in init.cpp
151 init_globals_ext();
152 }
153
154 // File names are case-insensitive on windows only
155 // Override me as needed
156 static int file_name_strcmp(const char* s1, const char* s2);
157
158 // unset environment variable
159 static bool unsetenv(const char* name);
160
161 static bool have_special_privileges();
162
163 static jlong javaTimeMillis();
164 static jlong javaTimeNanos();
165 static void javaTimeNanos_info(jvmtiTimerInfo *info_ptr);
166 static void javaTimeSystemUTC(jlong &seconds, jlong &nanos);
167 static void run_periodic_checks();
168 static bool supports_monotonic_clock();
169
170 // Returns the elapsed time in seconds since the vm started.
171 static double elapsedTime();
172
173 // Returns real time in seconds since an arbitrary point
174 // in the past.
175 static bool getTimesSecs(double* process_real_time,
176 double* process_user_time,
177 double* process_system_time);
178
179 // Interface to the performance counter
180 static jlong elapsed_counter();
181 static jlong elapsed_frequency();
182
183 // The "virtual time" of a thread is the amount of time a thread has
184 // actually run. The first function indicates whether the OS supports
185 // this functionality for the current thread, and if so:
186 // * the second enables vtime tracking (if that is required).
187 // * the third tells whether vtime is enabled.
188 // * the fourth returns the elapsed virtual time for the current
189 // thread.
190 static bool supports_vtime();
191 static bool enable_vtime();
192 static bool vtime_enabled();
193 static double elapsedVTime();
194
195 // Return current local time in a string (YYYY-MM-DD HH:MM:SS).
196 // It is MT safe, but not async-safe, as reading time zone
197 // information may require a lock on some platforms.
198 static char* local_time_string(char *buf, size_t buflen);
199 static struct tm* localtime_pd (const time_t* clock, struct tm* res);
200 static struct tm* gmtime_pd (const time_t* clock, struct tm* res);
201 // Fill in buffer with current local time as an ISO-8601 string.
202 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
203 // Returns buffer, or NULL if it failed.
204 static char* iso8601_time(char* buffer, size_t buffer_length, bool utc = false);
205
206 // Interface for detecting multiprocessor system
207 static inline bool is_MP() {
208 // During bootstrap if _processor_count is not yet initialized
209 // we claim to be MP as that is safest. If any platform has a
210 // stub generator that might be triggered in this phase and for
211 // which being declared MP when in fact not, is a problem - then
212 // the bootstrap routine for the stub generator needs to check
213 // the processor count directly and leave the bootstrap routine
214 // in place until called after initialization has ocurred.
215 return (_processor_count != 1) || AssumeMP;
216 }
217 static julong available_memory();
218 static julong physical_memory();
219 static bool has_allocatable_memory_limit(julong* limit);
220 static bool is_server_class_machine();
221
222 // number of CPUs
223 static int processor_count() {
224 return _processor_count;
225 }
226 static void set_processor_count(int count) { _processor_count = count; }
227
228 // Returns the number of CPUs this process is currently allowed to run on.
229 // Note that on some OSes this can change dynamically.
230 static int active_processor_count();
231
232 // At startup the number of active CPUs this process is allowed to run on.
233 // This value does not change dynamically. May be different from active_processor_count().
234 static int initial_active_processor_count() {
235 assert(_initial_active_processor_count > 0, "Initial active processor count not set yet.");
236 return _initial_active_processor_count;
237 }
238
239 // Bind processes to processors.
240 // This is a two step procedure:
241 // first you generate a distribution of processes to processors,
242 // then you bind processes according to that distribution.
243 // Compute a distribution for number of processes to processors.
244 // Stores the processor id's into the distribution array argument.
245 // Returns true if it worked, false if it didn't.
246 static bool distribute_processes(uint length, uint* distribution);
247 // Binds the current process to a processor.
248 // Returns true if it worked, false if it didn't.
249 static bool bind_to_processor(uint processor_id);
250
251 // Give a name to the current thread.
252 static void set_native_thread_name(const char *name);
253
254 // Interface for stack banging (predetect possible stack overflow for
255 // exception processing) There are guard pages, and above that shadow
256 // pages for stack overflow checking.
257 static bool uses_stack_guard_pages();
258 static bool must_commit_stack_guard_pages();
259 static void map_stack_shadow_pages(address sp);
260 static bool stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp);
261
262 // OS interface to Virtual Memory
263
264 // Return the default page size.
265 static int vm_page_size();
266
267 // Returns the page size to use for a region of memory.
268 // region_size / min_pages will always be greater than or equal to the
269 // returned value. The returned value will divide region_size.
270 static size_t page_size_for_region_aligned(size_t region_size, size_t min_pages);
271
272 // Returns the page size to use for a region of memory.
273 // region_size / min_pages will always be greater than or equal to the
274 // returned value. The returned value might not divide region_size.
275 static size_t page_size_for_region_unaligned(size_t region_size, size_t min_pages);
276
277 // Return the largest page size that can be used
278 static size_t max_page_size() {
279 // The _page_sizes array is sorted in descending order.
280 return _page_sizes[0];
281 }
282
283 // Methods for tracing page sizes returned by the above method.
284 // The region_{min,max}_size parameters should be the values
285 // passed to page_size_for_region() and page_size should be the result of that
286 // call. The (optional) base and size parameters should come from the
287 // ReservedSpace base() and size() methods.
288 static void trace_page_sizes(const char* str, const size_t* page_sizes, int count);
289 static void trace_page_sizes(const char* str,
290 const size_t region_min_size,
291 const size_t region_max_size,
292 const size_t page_size,
293 const char* base,
294 const size_t size);
295 static void trace_page_sizes_for_requested_size(const char* str,
296 const size_t requested_size,
297 const size_t page_size,
298 const size_t alignment,
299 const char* base,
300 const size_t size);
301
302 static int vm_allocation_granularity();
303 static char* reserve_memory(size_t bytes, char* addr = 0,
304 size_t alignment_hint = 0);
305 static char* reserve_memory(size_t bytes, char* addr,
306 size_t alignment_hint, MEMFLAGS flags);
307 static char* reserve_memory_aligned(size_t size, size_t alignment);
308 static char* attempt_reserve_memory_at(size_t bytes, char* addr);
309 static void split_reserved_memory(char *base, size_t size,
310 size_t split, bool realloc);
311 static bool commit_memory(char* addr, size_t bytes, bool executable);
312 static bool commit_memory(char* addr, size_t size, size_t alignment_hint,
313 bool executable);
314 // Same as commit_memory() that either succeeds or calls
315 // vm_exit_out_of_memory() with the specified mesg.
316 static void commit_memory_or_exit(char* addr, size_t bytes,
317 bool executable, const char* mesg);
318 static void commit_memory_or_exit(char* addr, size_t size,
319 size_t alignment_hint,
320 bool executable, const char* mesg);
321 static bool uncommit_memory(char* addr, size_t bytes);
322 static bool release_memory(char* addr, size_t bytes);
323
324 // Touch memory pages that cover the memory range from start to end (exclusive)
325 // to make the OS back the memory range with actual memory.
326 // Current implementation may not touch the last page if unaligned addresses
327 // are passed.
328 static void pretouch_memory(void* start, void* end, size_t page_size = vm_page_size());
329
330 enum ProtType { MEM_PROT_NONE, MEM_PROT_READ, MEM_PROT_RW, MEM_PROT_RWX };
331 static bool protect_memory(char* addr, size_t bytes, ProtType prot,
332 bool is_committed = true);
333
334 static bool guard_memory(char* addr, size_t bytes);
335 static bool unguard_memory(char* addr, size_t bytes);
336 static bool create_stack_guard_pages(char* addr, size_t bytes);
337 static bool pd_create_stack_guard_pages(char* addr, size_t bytes);
338 static bool remove_stack_guard_pages(char* addr, size_t bytes);
339
340 static char* map_memory(int fd, const char* file_name, size_t file_offset,
341 char *addr, size_t bytes, bool read_only = false,
342 bool allow_exec = false);
343 static char* remap_memory(int fd, const char* file_name, size_t file_offset,
344 char *addr, size_t bytes, bool read_only,
345 bool allow_exec);
346 static bool unmap_memory(char *addr, size_t bytes);
347 static void free_memory(char *addr, size_t bytes, size_t alignment_hint);
348 static void realign_memory(char *addr, size_t bytes, size_t alignment_hint);
349
350 // NUMA-specific interface
351 static bool numa_has_static_binding();
352 static bool numa_has_group_homing();
353 static void numa_make_local(char *addr, size_t bytes, int lgrp_hint);
354 static void numa_make_global(char *addr, size_t bytes);
355 static size_t numa_get_groups_num();
356 static size_t numa_get_leaf_groups(int *ids, size_t size);
357 static bool numa_topology_changed();
358 static int numa_get_group_id();
359
360 // Page manipulation
361 struct page_info {
362 size_t size;
363 int lgrp_id;
364 };
365 static bool get_page_info(char *start, page_info* info);
366 static char* scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found);
367
368 static char* non_memory_address_word();
369 // reserve, commit and pin the entire memory region
370 static char* reserve_memory_special(size_t size, size_t alignment,
371 char* addr, bool executable);
372 static bool release_memory_special(char* addr, size_t bytes);
373 static void large_page_init();
374 static size_t large_page_size();
375 static bool can_commit_large_page_memory();
376 static bool can_execute_large_page_memory();
377
378 // OS interface to polling page
379 static address get_polling_page() { return _polling_page; }
380 static void set_polling_page(address page) { _polling_page = page; }
381 static bool is_poll_address(address addr) { return addr >= _polling_page && addr < (_polling_page + os::vm_page_size()); }
382 static void make_polling_page_unreadable();
383 static void make_polling_page_readable();
384
385 // Routines used to serialize the thread state without using membars
386 static void serialize_thread_states();
387
388 // Since we write to the serialize page from every thread, we
389 // want stores to be on unique cache lines whenever possible
390 // in order to minimize CPU cross talk. We pre-compute the
391 // amount to shift the thread* to make this offset unique to
392 // each thread.
393 static int get_serialize_page_shift_count() {
394 return SerializePageShiftCount;
395 }
396
397 static void set_serialize_page_mask(uintptr_t mask) {
398 _serialize_page_mask = mask;
399 }
400
401 static unsigned int get_serialize_page_mask() {
402 return _serialize_page_mask;
403 }
404
405 static void set_memory_serialize_page(address page);
406
407 static address get_memory_serialize_page() {
408 return (address)_mem_serialize_page;
409 }
410
411 static inline void write_memory_serialize_page(JavaThread *thread) {
412 uintptr_t page_offset = ((uintptr_t)thread >>
413 get_serialize_page_shift_count()) &
414 get_serialize_page_mask();
415 *(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
416 }
417
418 static bool is_memory_serialize_page(JavaThread *thread, address addr) {
419 if (UseMembar) return false;
420 // Previously this function calculated the exact address of this
421 // thread's serialize page, and checked if the faulting address
422 // was equal. However, some platforms mask off faulting addresses
423 // to the page size, so now we just check that the address is
424 // within the page. This makes the thread argument unnecessary,
425 // but we retain the NULL check to preserve existing behavior.
426 if (thread == NULL) return false;
427 address page = (address) _mem_serialize_page;
428 return addr >= page && addr < (page + os::vm_page_size());
429 }
430
431 static void block_on_serialize_page_trap();
432
433 // threads
434
435 enum ThreadType {
436 vm_thread,
437 cgc_thread, // Concurrent GC thread
438 pgc_thread, // Parallel GC thread
439 java_thread, // Java, CodeCacheSweeper, JVMTIAgent and Service threads.
440 compiler_thread,
441 watcher_thread,
442 os_thread
443 };
444
445 static bool create_thread(Thread* thread,
446 ThreadType thr_type,
447 size_t req_stack_size = 0);
448 static bool create_main_thread(JavaThread* thread);
449 static bool create_attached_thread(JavaThread* thread);
450 static void pd_start_thread(Thread* thread);
451 static void start_thread(Thread* thread);
452
453 static void initialize_thread(Thread* thr);
454 static void free_thread(OSThread* osthread);
455
456 // thread id on Linux/64bit is 64bit, on Windows and Solaris, it's 32bit
457 static intx current_thread_id();
458 static int current_process_id();
459 static int sleep(Thread* thread, jlong ms, bool interruptable);
460 // Short standalone OS sleep suitable for slow path spin loop.
461 // Ignores Thread.interrupt() (so keep it short).
462 // ms = 0, will sleep for the least amount of time allowed by the OS.
463 static void naked_short_sleep(jlong ms);
464 static void infinite_sleep(); // never returns, use with CAUTION
465 static void naked_yield () ;
466 static OSReturn set_priority(Thread* thread, ThreadPriority priority);
467 static OSReturn get_priority(const Thread* const thread, ThreadPriority& priority);
468
469 static void interrupt(Thread* thread);
470 static bool is_interrupted(Thread* thread, bool clear_interrupted);
471
472 static int pd_self_suspend_thread(Thread* thread);
473
474 static ExtendedPC fetch_frame_from_context(const void* ucVoid, intptr_t** sp, intptr_t** fp);
475 static frame fetch_frame_from_context(const void* ucVoid);
476 static frame fetch_frame_from_ucontext(Thread* thread, void* ucVoid);
477
478 static ExtendedPC get_thread_pc(Thread *thread);
479 static void breakpoint();
480 static bool start_debugging(char *buf, int buflen);
481
482 static address current_stack_pointer();
483 static address current_stack_base();
484 static size_t current_stack_size();
485
486 static void verify_stack_alignment() PRODUCT_RETURN;
487
488 static bool message_box(const char* title, const char* message);
489 static char* do_you_want_to_debug(const char* message);
490
491 // run cmd in a separate process and return its exit code; or -1 on failures
492 static int fork_and_exec(char *cmd);
493
494 // Call ::exit() on all platforms but Windows
495 static void exit(int num);
496
497 // Terminate the VM, but don't exit the process
498 static void shutdown();
499
500 // Terminate with an error. Default is to generate a core file on platforms
501 // that support such things. This calls shutdown() and then aborts.
502 static void abort(bool dump_core, void *siginfo, const void *context);
503 static void abort(bool dump_core = true);
504
505 // Die immediately, no exit hook, no abort hook, no cleanup.
506 static void die();
507
508 // File i/o operations
509 static const int default_file_open_flags();
510 static int open(const char *path, int oflag, int mode);
511 static FILE* open(int fd, const char* mode);
512 static int close(int fd);
513 static jlong lseek(int fd, jlong offset, int whence);
514 static char* native_path(char *path);
515 static int ftruncate(int fd, jlong length);
516 static int fsync(int fd);
517 static int available(int fd, jlong *bytes);
518 static int get_fileno(FILE* fp);
519 static void flockfile(FILE* fp);
520 static void funlockfile(FILE* fp);
521
522 static int compare_file_modified_times(const char* file1, const char* file2);
523
524 //File i/o operations
525
526 static size_t read(int fd, void *buf, unsigned int nBytes);
527 static size_t read_at(int fd, void *buf, unsigned int nBytes, jlong offset);
528 static size_t restartable_read(int fd, void *buf, unsigned int nBytes);
529 static size_t write(int fd, const void *buf, unsigned int nBytes);
530
531 // Reading directories.
532 static DIR* opendir(const char* dirname);
533 static int readdir_buf_size(const char *path);
534 static struct dirent* readdir(DIR* dirp, dirent* dbuf);
535 static int closedir(DIR* dirp);
536
537 // Dynamic library extension
538 static const char* dll_file_extension();
539
540 static const char* get_temp_directory();
541 static const char* get_current_directory(char *buf, size_t buflen);
542
543 // Builds a platform-specific full library path given a ld path and lib name
544 // Returns true if buffer contains full path to existing file, false otherwise
545 static bool dll_build_name(char* buffer, size_t size,
546 const char* pathname, const char* fname);
547
548 // Symbol lookup, find nearest function name; basically it implements
549 // dladdr() for all platforms. Name of the nearest function is copied
550 // to buf. Distance from its base address is optionally returned as offset.
551 // If function name is not found, buf[0] is set to '\0' and offset is
552 // set to -1 (if offset is non-NULL).
553 static bool dll_address_to_function_name(address addr, char* buf,
554 int buflen, int* offset,
555 bool demangle = true);
556
557 // Locate DLL/DSO. On success, full path of the library is copied to
558 // buf, and offset is optionally set to be the distance between addr
559 // and the library's base address. On failure, buf[0] is set to '\0'
560 // and offset is set to -1 (if offset is non-NULL).
561 static bool dll_address_to_library_name(address addr, char* buf,
562 int buflen, int* offset);
563
564 // Find out whether the pc is in the static code for jvm.dll/libjvm.so.
565 static bool address_is_in_vm(address addr);
566
567 // Loads .dll/.so and
568 // in case of error it checks if .dll/.so was built for the
569 // same architecture as HotSpot is running on
570 static void* dll_load(const char *name, char *ebuf, int ebuflen);
571
572 // lookup symbol in a shared library
573 static void* dll_lookup(void* handle, const char* name);
574
575 // Unload library
576 static void dll_unload(void *lib);
577
578 // Callback for loaded module information
579 // Input parameters:
580 // char* module_file_name,
581 // address module_base_addr,
582 // address module_top_addr,
583 // void* param
584 typedef int (*LoadedModulesCallbackFunc)(const char *, address, address, void *);
585
586 static int get_loaded_modules_info(LoadedModulesCallbackFunc callback, void *param);
587
588 // Return the handle of this process
589 static void* get_default_process_handle();
590
591 // Check for static linked agent library
592 static bool find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
593 size_t syms_len);
594
595 // Find agent entry point
596 static void *find_agent_function(AgentLibrary *agent_lib, bool check_lib,
597 const char *syms[], size_t syms_len);
598
599 // Write to stream
600 static int log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) ATTRIBUTE_PRINTF(3, 0);
601
602 // Get host name in buffer provided
603 static bool get_host_name(char* buf, size_t buflen);
604
605 // Print out system information; they are called by fatal error handler.
606 // Output format may be different on different platforms.
607 static void print_os_info(outputStream* st);
608 static void print_os_info_brief(outputStream* st);
609 static void print_cpu_info(outputStream* st, char* buf, size_t buflen);
610 static void pd_print_cpu_info(outputStream* st, char* buf, size_t buflen);
611 static void print_summary_info(outputStream* st, char* buf, size_t buflen);
612 static void print_memory_info(outputStream* st);
613 static void print_dll_info(outputStream* st);
614 static void print_environment_variables(outputStream* st, const char** env_list);
615 static void print_context(outputStream* st, const void* context);
616 static void print_register_info(outputStream* st, const void* context);
617 static void print_siginfo(outputStream* st, const void* siginfo);
618 static void print_signal_handlers(outputStream* st, char* buf, size_t buflen);
619 static void print_date_and_time(outputStream* st, char* buf, size_t buflen);
620
621 static void print_location(outputStream* st, intptr_t x, bool verbose = false);
622 static size_t lasterror(char *buf, size_t len);
623 static int get_last_error();
624
625 // Replacement for strerror().
626 // Will return the english description of the error (e.g. "File not found", as
627 // suggested in the POSIX standard.
628 // Will return "Unknown error" for an unknown errno value.
629 // Will not attempt to localize the returned string.
630 // Will always return a valid string which is a static constant.
631 // Will not change the value of errno.
632 static const char* strerror(int e);
633
634 // Will return the literalized version of the given errno (e.g. "EINVAL"
635 // for EINVAL).
636 // Will return "Unknown error" for an unknown errno value.
637 // Will always return a valid string which is a static constant.
638 // Will not change the value of errno.
639 static const char* errno_name(int e);
640
641 // Determines whether the calling process is being debugged by a user-mode debugger.
642 static bool is_debugger_attached();
643
644 // wait for a key press if PauseAtExit is set
645 static void wait_for_keypress_at_exit(void);
646
647 // The following two functions are used by fatal error handler to trace
648 // native (C) frames. They are not part of frame.hpp/frame.cpp because
649 // frame.hpp/cpp assume thread is JavaThread, and also because different
650 // OS/compiler may have different convention or provide different API to
651 // walk C frames.
652 //
653 // We don't attempt to become a debugger, so we only follow frames if that
654 // does not require a lookup in the unwind table, which is part of the binary
655 // file but may be unsafe to read after a fatal error. So on x86, we can
656 // only walk stack if %ebp is used as frame pointer; on ia64, it's not
657 // possible to walk C stack without having the unwind table.
658 static bool is_first_C_frame(frame *fr);
659 static frame get_sender_for_C_frame(frame *fr);
660
661 // return current frame. pc() and sp() are set to NULL on failure.
662 static frame current_frame();
663
664 static void print_hex_dump(outputStream* st, address start, address end, int unitsize);
665
666 // returns a string to describe the exception/signal;
667 // returns NULL if exception_code is not an OS exception/signal.
668 static const char* exception_name(int exception_code, char* buf, size_t buflen);
669
670 // Returns the signal number (e.g. 11) for a given signal name (SIGSEGV).
671 static int get_signal_number(const char* signal_name);
672
673 // Returns native Java library, loads if necessary
674 static void* native_java_library();
675
676 // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
677 static void jvm_path(char *buf, jint buflen);
678
679 // Returns true if we are running in a headless jre.
680 static bool is_headless_jre();
681
682 // JNI names
683 static void print_jni_name_prefix_on(outputStream* st, int args_size);
684 static void print_jni_name_suffix_on(outputStream* st, int args_size);
685
686 // Init os specific system properties values
687 static void init_system_properties_values();
688
689 // IO operations, non-JVM_ version.
690 static int stat(const char* path, struct stat* sbuf);
691 static bool dir_is_empty(const char* path);
692
693 // IO operations on binary files
694 static int create_binary_file(const char* path, bool rewrite_existing);
695 static jlong current_file_offset(int fd);
696 static jlong seek_to_file_offset(int fd, jlong offset);
697
698 // Retrieve native stack frames.
699 // Parameter:
700 // stack: an array to storage stack pointers.
701 // frames: size of above array.
702 // toSkip: number of stack frames to skip at the beginning.
703 // Return: number of stack frames captured.
704 static int get_native_stack(address* stack, int size, int toSkip = 0);
705
706 // General allocation (must be MT-safe)
707 static void* malloc (size_t size, MEMFLAGS flags, const NativeCallStack& stack);
708 static void* malloc (size_t size, MEMFLAGS flags);
709 static void* realloc (void *memblock, size_t size, MEMFLAGS flag, const NativeCallStack& stack);
710 static void* realloc (void *memblock, size_t size, MEMFLAGS flag);
711
712 static void free (void *memblock);
713 static char* strdup(const char *, MEMFLAGS flags = mtInternal); // Like strdup
714 // Like strdup, but exit VM when strdup() returns NULL
715 static char* strdup_check_oom(const char*, MEMFLAGS flags = mtInternal);
716
717 #ifndef PRODUCT
718 static julong num_mallocs; // # of calls to malloc/realloc
719 static julong alloc_bytes; // # of bytes allocated
720 static julong num_frees; // # of calls to free
721 static julong free_bytes; // # of bytes freed
722 #endif
723
724 // SocketInterface (ex HPI SocketInterface )
725 static int socket(int domain, int type, int protocol);
726 static int socket_close(int fd);
727 static int recv(int fd, char* buf, size_t nBytes, uint flags);
728 static int send(int fd, char* buf, size_t nBytes, uint flags);
729 static int raw_send(int fd, char* buf, size_t nBytes, uint flags);
730 static int connect(int fd, struct sockaddr* him, socklen_t len);
731 static struct hostent* get_host_by_name(char* name);
732
733 // Support for signals (see JVM_RaiseSignal, JVM_RegisterSignal)
734 static void signal_init(TRAPS);
735 static void signal_init_pd();
736 static void signal_notify(int signal_number);
737 static void* signal(int signal_number, void* handler);
738 static void signal_raise(int signal_number);
739 static int signal_wait();
740 static int signal_lookup();
741 static void* user_handler();
742 static void terminate_signal_thread();
743 static int sigexitnum_pd();
744
745 // random number generation
746 static long random(); // return 32bit pseudorandom number
747 static void init_random(long initval); // initialize random sequence
748
749 // Structured OS Exception support
750 static void os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, Thread* thread);
751
752 // On Posix compatible OS it will simply check core dump limits while on Windows
753 // it will check if dump file can be created. Check or prepare a core dump to be
754 // taken at a later point in the same thread in os::abort(). Use the caller
755 // provided buffer as a scratch buffer. The status message which will be written
756 // into the error log either is file location or a short error message, depending
757 // on the checking result.
758 static void check_dump_limit(char* buffer, size_t bufferSize);
759
760 // Get the default path to the core file
761 // Returns the length of the string
762 static int get_core_path(char* buffer, size_t bufferSize);
763
764 // JVMTI & JVM monitoring and management support
765 // The thread_cpu_time() and current_thread_cpu_time() are only
766 // supported if is_thread_cpu_time_supported() returns true.
767 // They are not supported on Solaris T1.
768
769 // Thread CPU Time - return the fast estimate on a platform
770 // On Solaris - call gethrvtime (fast) - user time only
771 // On Linux - fast clock_gettime where available - user+sys
772 // - otherwise: very slow /proc fs - user+sys
773 // On Windows - GetThreadTimes - user+sys
774 static jlong current_thread_cpu_time();
775 static jlong thread_cpu_time(Thread* t);
776
777 // Thread CPU Time with user_sys_cpu_time parameter.
778 //
779 // If user_sys_cpu_time is true, user+sys time is returned.
780 // Otherwise, only user time is returned
781 static jlong current_thread_cpu_time(bool user_sys_cpu_time);
782 static jlong thread_cpu_time(Thread* t, bool user_sys_cpu_time);
783
784 // Return a bunch of info about the timers.
785 // Note that the returned info for these two functions may be different
786 // on some platforms
787 static void current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
788 static void thread_cpu_time_info(jvmtiTimerInfo *info_ptr);
789
790 static bool is_thread_cpu_time_supported();
791
792 // System loadavg support. Returns -1 if load average cannot be obtained.
793 static int loadavg(double loadavg[], int nelem);
794
795 // Hook for os specific jvm options that we don't want to abort on seeing
796 static bool obsolete_option(const JavaVMOption *option);
797
798 // Amount beyond the callee frame size that we bang the stack.
799 static int extra_bang_size_in_bytes();
800
801 static char** split_path(const char* path, int* n);
802
803 // Extensions
804 #include "runtime/os_ext.hpp"
805
806 public:
807 class CrashProtectionCallback : public StackObj {
808 public:
809 virtual void call() = 0;
810 };
811
812 // Platform dependent stuff
813 #ifndef _WINDOWS
814 # include "os_posix.hpp"
815 #endif
816 #include OS_CPU_HEADER(os)
817 #include OS_HEADER(os)
818
819 #ifndef OS_NATIVE_THREAD_CREATION_FAILED_MSG
820 #define OS_NATIVE_THREAD_CREATION_FAILED_MSG "unable to create native thread: possibly out of memory or process/resource limits reached"
821 #endif
822
823 public:
824 #ifndef PLATFORM_PRINT_NATIVE_STACK
825 // No platform-specific code for printing the native stack.
826 static bool platform_print_native_stack(outputStream* st, const void* context,
827 char *buf, int buf_size) {
828 return false;
829 }
830 #endif
831
832 // debugging support (mostly used by debug.cpp but also fatal error handler)
833 static bool find(address pc, outputStream* st = tty); // OS specific function to make sense out of an address
834
835 static bool dont_yield(); // when true, JVM_Yield() is nop
836 static void print_statistics();
837
838 // Thread priority helpers (implemented in OS-specific part)
839 static OSReturn set_native_priority(Thread* thread, int native_prio);
840 static OSReturn get_native_priority(const Thread* const thread, int* priority_ptr);
841 static int java_to_os_priority[CriticalPriority + 1];
842 // Hint to the underlying OS that a task switch would not be good.
843 // Void return because it's a hint and can fail.
844 static void hint_no_preempt();
845 static const char* native_thread_creation_failed_msg() {
846 return OS_NATIVE_THREAD_CREATION_FAILED_MSG;
847 }
848
849 // Used at creation if requested by the diagnostic flag PauseAtStartup.
850 // Causes the VM to wait until an external stimulus has been applied
851 // (for Unix, that stimulus is a signal, for Windows, an external
852 // ResumeThread call)
853 static void pause();
854
855 // Builds a platform dependent Agent_OnLoad_<libname> function name
856 // which is used to find statically linked in agents.
857 static char* build_agent_function_name(const char *sym, const char *cname,
858 bool is_absolute_path);
859
860 class SuspendedThreadTaskContext {
861 public:
862 SuspendedThreadTaskContext(Thread* thread, void *ucontext) : _thread(thread), _ucontext(ucontext) {}
863 Thread* thread() const { return _thread; }
864 void* ucontext() const { return _ucontext; }
865 private:
866 Thread* _thread;
867 void* _ucontext;
868 };
869
870 class SuspendedThreadTask {
871 public:
872 SuspendedThreadTask(Thread* thread) : _thread(thread), _done(false) {}
873 virtual ~SuspendedThreadTask() {}
874 void run();
875 bool is_done() { return _done; }
876 virtual void do_task(const SuspendedThreadTaskContext& context) = 0;
877 protected:
878 private:
879 void internal_do_task();
880 Thread* _thread;
881 bool _done;
882 };
883
884 #ifndef _WINDOWS
885 // Suspend/resume support
886 // Protocol:
887 //
888 // a thread starts in SR_RUNNING
889 //
890 // SR_RUNNING can go to
891 // * SR_SUSPEND_REQUEST when the WatcherThread wants to suspend it
892 // SR_SUSPEND_REQUEST can go to
893 // * SR_RUNNING if WatcherThread decides it waited for SR_SUSPENDED too long (timeout)
894 // * SR_SUSPENDED if the stopped thread receives the signal and switches state
895 // SR_SUSPENDED can go to
896 // * SR_WAKEUP_REQUEST when the WatcherThread has done the work and wants to resume
897 // SR_WAKEUP_REQUEST can go to
898 // * SR_RUNNING when the stopped thread receives the signal
899 // * SR_WAKEUP_REQUEST on timeout (resend the signal and try again)
900 class SuspendResume {
901 public:
902 enum State {
903 SR_RUNNING,
904 SR_SUSPEND_REQUEST,
905 SR_SUSPENDED,
906 SR_WAKEUP_REQUEST
907 };
908
909 private:
910 volatile State _state;
911
912 private:
913 /* try to switch state from state "from" to state "to"
914 * returns the state set after the method is complete
915 */
916 State switch_state(State from, State to);
917
918 public:
919 SuspendResume() : _state(SR_RUNNING) { }
920
921 State state() const { return _state; }
922
923 State request_suspend() {
924 return switch_state(SR_RUNNING, SR_SUSPEND_REQUEST);
925 }
926
927 State cancel_suspend() {
928 return switch_state(SR_SUSPEND_REQUEST, SR_RUNNING);
929 }
930
931 State suspended() {
932 return switch_state(SR_SUSPEND_REQUEST, SR_SUSPENDED);
933 }
934
935 State request_wakeup() {
936 return switch_state(SR_SUSPENDED, SR_WAKEUP_REQUEST);
937 }
938
939 State running() {
940 return switch_state(SR_WAKEUP_REQUEST, SR_RUNNING);
941 }
942
943 bool is_running() const {
944 return _state == SR_RUNNING;
945 }
946
947 bool is_suspend_request() const {
948 return _state == SR_SUSPEND_REQUEST;
949 }
950
951 bool is_suspended() const {
952 return _state == SR_SUSPENDED;
953 }
954 };
955 #endif // !WINDOWS
956
957
958 protected:
959 static long _rand_seed; // seed for random number generator
960 static int _processor_count; // number of processors
961 static int _initial_active_processor_count; // number of active processors during initialization.
962
963 static char* format_boot_path(const char* format_string,
964 const char* home,
965 int home_len,
966 char fileSep,
967 char pathSep);
968 static bool set_boot_path(char fileSep, char pathSep);
969
970 };
971
972 // Note that "PAUSE" is almost always used with synchronization
973 // so arguably we should provide Atomic::SpinPause() instead
974 // of the global SpinPause() with C linkage.
975 // It'd also be eligible for inlining on many platforms.
976
977 extern "C" int SpinPause();
978
979 #endif // SHARE_VM_RUNTIME_OS_HPP